Pinpointing WTC Pollution

A new simulation tracks the movement of debris on 9/11 and may help pin down which residents' health is at risk.

With a recent report showing that almost 70 percent of World Trade Center first responders have had lung problems, there's new concern for people who lived in the area. Scientists have developed a new computer model to determine who's been most affected by the smoke and ash.

Health officials still don't know the full impact to communities surrounding the World Trade Center, since the few air monitors in New York responsible for testing air quality became clogged during the time or lost power. "There was a very limited amount of monitoring data, and you wouldn't expect much more," says Paul Lioy, an environmental health scientist at the Environmental & Occupational Health Sciences Institute, part of Rutgers and the University of Medicine & Dentistry of New Jersey–Robert Wood Johnson Medical School.

Now, researchers have developed a computer simulation of the plume of smoke and airborne dust from the collapse and continued burning of the World Trade Center. Rutgers University scientist Georgiy Stenchikov worked with Lioy and others to create the most up-to-date air contaminant model, using data about the region's wind, temperature, and humidity to supplement surface and space-based observations. Stenchikov's team was able to reconstruct the precise location and concentration of the plume for up to a month after September 11.

"Mostly affected were the people who were in the vicinity of the World Trade Center," Stanchikov says. "But still it is very important to know how this concentration was distributed." While the computer model produces an impressive animation of the plume, Lioy says that the model also produces valuable data to pinpoint how people might have been affected individually. "We can actually come up with an index for each day, to say whether you were highly exposed or a non-exposed individual," he says.

As they wrote in the journal Environmental Fluid Mechanics, the results of their model matched the results from the few air monitors that were functioning around New York City. Their model shows that communities southeast of the World Trade Center had higher levels of exposure. The plume also reached the borough of Brooklyn, but the levels of airborne contaminants were ten times less. Stenchikov and Lioy say that future research is needed to determine the health effects on populations at these different levels of exposure.